Secure and efficient blockchain-assisted group authentication scheme for vehicular digital twin

Vehicular networks, such as vehicular ad-hoc networks (VANETs), have supported connected vehicle technologies to enable convenient applications like traffic monitoring. To overcome the limitations of vehicular networks, including constrained computation and communication barriers, the vehicular digital twin (VDT) has gained increasing attention. By leveraging a digital twin (DT) that replicates physical objects as their virtual counterparts in digital environments, the VDT collects and analyzes traffic data over public channels, which may lead to potential security and privacy concerns. Existing authentication schemes based on public key infrastructure (PKI) and blockchain (BC) may face challenges in VDTs, as certain PKI operations can introduce latency, and BC provides limited support for authentication. Moreover, current DT authentication protocols are not tailored for secure communication in VDT networks or often incur significant overhead. In this paper, we propose a secure and efficient authentication scheme for the VDT. We introduce a group-based communication scheme that ensures seamless authentication during handovers through group key agreements. Additionally, our scheme integrates BC with a lightweight digital signature to address the lack of authentication and mitigate a single point of failure (SPOF), while ensuring tamper-resistant data during communication. Security analysis, including comparisons with prior works, demonstrates that our scheme effectively addresses security concerns. The performance evaluation results further demonstrate that the proposed scheme significantly reduces both computation and communication overhead, highlighting its efficiency.